Creating a Successful Apple Orchard
There is a great difference between planting an orchard that survives and one that thrives. To create an orchard that grows well and produces quality apples, there are several considerations that should be addressed before any apple trees are planted.
SITE
The site chosen for an orchard can mean the difference between having a crop, or no crop. The most important factor is the occurrence of frosts during flowering. In a low-lying site, cold air will pool during still nights and frosts are likely to occur. A site on a hill where air is draining down toward a lower area, or a site near a large body of water that moderates the temperature, will be far less likely to experience frosts during this critical period. While most of us have little choice in placing an orchard, siting in the most advantageous position will play an important role in its success.
SOIL
Soil is the basis of all life, but soils differ tremendously in their ability to provide nutrients to an apple tree. To provide the needs of the apple tree, a soil should contain the elements required to create healthy foliage and fruit.
Soils are composed of three basic ingredients - sand, clay, and silt. Soils that are sand based may be lacking in some of these elements, as sand is essentially silica, and will only break down over time periods that are beyond our reckoning. In such soils the nutrients needed must be provided by organic matter, which is the remains of plants and animals. If the soil has little other than silica sand and stone, the task of providing enough organic matter may be difficult to near impossible.
Clay soils have both advantages and disadvantages. Clays usually contain a host of elements and are far more productive than sandy soils, but if the percentage of clay to sand and/or silt is too high there can be problems with drainage, and the denser texture may not allow easy access by the roots.
Soils with a high silt content are far less common, however such soils are usually very productive.
The ideal soil is a blend of sand, clay, and silt. Such soils can provide a wealth of nutrients and will have good drainage. Good drainage is essential for a successful apple orchard. In poorly drained soils the roots may be subject to long periods when the soil around them is saturated. The lack of oxygen will inevitably suffocate the roots. It can also create a condition where the roots of the tree can only exist near the surface. Shallow roots will not be able to properly support the tree during high winds, especially if there is a large crop.
If the soil does not drain well, drainage can be provided by installing perforated drainpipes that carry away excess water. These should be located below the root zone. You can also form the land so the rows of trees are on built up berms separated by lower swales that carry the water away. It is obvious that such measures add a great deal to the cost of an orchard, and may still not create the ideal conditions the trees need.
The best orchard soils are well drained sandy or clay loams with high organic matter content. The organic matter is vital to growth, as its gradual breakdown releases the nutrients it contains, and its spongy texture helps hold both air and water.
While less than ideal soils can be adjusted, such measures will add considerably to the cost of establishment.
SOIL pH
Another soil related issue is its acidity level. This level is measured using the pH (potential hydrogen) scale. The scale runs from 0 (think hydrochloric acid) to 14 (think lye). In this system 7 is neutral, neither acidic nor alkaline. Apples grow best in soils with a pH of 6.5-7.0. In more acidic soils, many nutrients such as calcium and magnesium are chemically bound up in molecules that cannot be accessed by the roots. If ground limestone is added according to need, the pH can be raised over a period of years to the desired level and maintained by the addition of lime every six years or so. As the pH nears neutral, the elements are released from their bonds and become free floating ions that are easily absorbed by the roots. Although not as common, if the soil is alkaline, sulfur can be added to lower the pH toward neutral. For young trees to grow to their potential, an orchard should not be planted until the pH is at the proper level.
SPACING
For the homeowner, placing a few trees in a yard is not a big issue, however if you are contemplating a larger orchard the spacing of trees becomes very important. Most commercial orchards are now planted in rows with trees placed around 1m (3ft) apart. These trees are grafted on dwarfing roots and will require permanent posts and wires to support them over the life of the orchard. If you choose a more traditionally spaced orchard, be sure to choose rootstocks that will provide good anchorage. Even if the trees will not be supported long term, be sure to stake the new trees for one year. This will prevent rocking of the trees in wind, which slows establishment, and will keep them straighter in the row and better balanced to hold a crop.
ROOTSTOCKS
An apple tree is both the cultivar (what most people call a variety) you want to harvest and the rootstock the top is grafted onto. The rootstock you use should be carefully chosen. Seedling rootstocks will vary in size, productivity, and the speed at which the cultivar comes into bearing. The advantage of seedlings lies is in their diversity. In a difficult winter, chances are not all trees will be affected. If you are growing on one type of clonal rootstock, then a possibility exists that all will be affected. The advantages of a clonal rootstock are that its size, productivity, and precocity (speed at which it comes into bearing) are known factors. There is more uniformity in the trees. There are now many clonal rootstocks available, and a bit of research will be invaluable to the future of your endeavor.
CULTIVARS (VARIETIES)
Just as important as the rootstocks are the cultivars you choose to grow. There are early, mid-season, and late cultivars. Generally speaking, the earlier apples do not keep as well and are most often used for cooking (sauces, baking, etc.). The later apples tend to be firmer and keep better. For a family’s use, one or two early apple cultivars will be enough once they are in full fruit. Usually, the bulk of the trees in an orchard will be later ripening.
There are hundreds of available apples. Choosing which to use is a question of taste, usage, hardiness, and disease resistance. These latter characteristics are of ultimate importance. You should choose apples that will survive your winters. Those that are injured by low temperatures will be prone to disease such as cankers and may even be killed. Disease resistant cultivars will make your life far easier. Luckily, there are now many disease-resistant apples available. Though you will still have insects to consider, the lack of fungal diseases such as apple scab, mildew, and cedar apple rust will decrease the burden of protection considerably.
INSECTS
There is no greater challenge in horticulture than producing high quality, clean apples using organic methods. Everything wants to eat the apple. The list of insects, birds and mammals that can create challenges for the grower are long. Dealing with this assemblage of pests is what will occupy you for the life of the orchard. However, this is an exciting and rewarding time to grow apples without the use of toxic chemicals. Here is a partial list of pests along with products and methods that can be used against them.
Apple maggot- The maggot flies rise from their wintering places in the soil in early to mid-summer (early July in N.B.) Use yellow plastic balls covered with a sticky substance such as Tanglefoot or sticky cards to lure the flies. These act as monitors. Once the first flies are caught it is time to protect the crop. The most effective product on the market today is Naturalyte (GF 120 commercially). This contains Spinosad, which is produced by soil microbes. It is non-toxic to mammals. Using a backpack sprayer with the spinner removed, you whip the wand a few times to put droplets on the underside of the leaves. You need only do this to every second or third tree in the row. The flies are attracted to these feeding stations and die after feeding on the droplets. Reapply after heavy rains or every week or so until near harvest. If well applied, you will have little or no maggot damage.
European sawfly-This insect emerges just before flowering and will feed on the flowers and the newly forming fruit. Their presence can be seen later as a spiral scar that emanates from the basin end of the apple. Later instars (stages of growth) will bore into the side of the fruit, rendering it useless. Entrust is another product containing Spinosad. It should be applied to the trees just before flowering or just after. Do not use during flowering, as it is toxic to bees.
Codling moth-The codling moth emerges after flowering, but its damage is seen later than the sawfly. It usually bores into the side of the apple and eats its way to the core. Larger orchards can use mating disruptors such as Isomate C-Plus, that are hung in the top of the tree. Over the season they release a synthetic pheromone that fills the air, thus confusing the male looking for a mate. Small orchards can place cardboard bands on the trunks in the late summer. The larvae will try to overwinter in these and can be destroyed.
Leafrollers-There are several leafrollers that feed on new growth and the developing apples. They roll up the tips of stems and will stunt growth and feed on the newly forming fruit, leaving scars. Just before flowering apply Btk (Bacillus thuringensis ‘Kurstaki’). This is a bacterium that only affects the larval stages of butterflies and moths. Once ingested, the insect stops feeding and dies. You may need to reapply in mid-summer. Monitor the foliage for any new damage to time the second spray.
FUNGI
The other major pests of apples are types of fungi that grow on the surface of the foliage and fruit. These arrive on the air emanating from the last year’s leaves and fallen fruit and from other trees in the area. Here are a few of the most important.
Apple scab-Scab forms lesions on the foliage and fruit that are brown to black in colour. Although the apples remain edible, they severely affect the appearance and make breakdown in storage more likely. Although dependent on temperature and humidity, generally the spores are released just prior to flowering. For organic growers a product called flowable sulfur can be used to prevent infection. Later, particularly after rainfalls, other sprays are advisable. The easiest way to avoid scab is to choose cultivars resistant to it. There are now many scab-resistant apples on the market.
Powdery mildew-Mildew overwinters in the buds and creates thread-like structures called mycelia that release spores as the flowers begin to open. They can severely affect growth and will affect the surface of the fruit. It does best when humidity is high, but does not flourish in rain, as the spores are washed away. Strangely enough, a spray of milk mixed at a ratio of one part milk to two parts water has been shown to be as effective as the fungicides used in the past. Reapply in early summer until the higher temperatures of summer arrive. Disease resistant cultivars are highly recommended, making prevention unnecessary.
Flyspeck and Sooty Blotch-These closely related diseases become noticeable on fruit at the end of the ripening season. They appear as tiny black dots or, as the name indicates, as sooty looking patches. They are most prevalent on fruit that is in the center of the tree where there is less air circulation. Although it does not affect the edibility of the fruit, it does affect the appearance. A spray of flowable sulfur in mid-season should prevent this fungus from developing.
European Canker-Canker most often develops where there has been winter injury, and most often in the crotches of trees. Using hardy cultivars is the best method of preventing its appearance. It will appear as sunken bark that appears black. If not dealt with, it can spread further and even pose a threat to the tree’s life. Once noticed, remove all affected tissue. Using a sharp knife, cut back the edges of the wound until a green edge (the cambium) is created. Paint the entire area with a latex paint.
BACTERIA
Fireblight-Monitoring the orchard for fireblight is essential, as once established in the orchard it can quickly spread to other trees. It infects the blossoms and/or the soft, growing tips of stems. The symptoms are blackened leaves and stem ends that often form a shepherd’s crook form. Remove the damage well below the infection site and destroy. Pruning shears should be dipped in alcohol after every cut to ensure transfer does not occur. Northern orchards are less prone to this disease, but warming trends are leading to more infections than in the past. Vigilance is required.
THE SATISFYING PART
If you have been attentive to the necessary activities listed above, you should be able to enjoy the best part of growing-the harvest. There is nothing more enjoyable than picking ripe clean fruit from your trees, knowing they have been raised by life affirming methods.